Typically, in sweeping machines of this type, the dirt container may be placed under operator control, either in an operating position, where the edge of its inlet opening is in sealed engagement with the edge of the discharge opening of the dirt delivery conduit, or in a raised position, from which the dirt container may be rotated under operator control into a dumping position to empty its contents.
Such floor-cleaning machines are known in various forms. For example, in some cases, a driven rotating brush, usually in the form of a cylinder sweeping brush is extended transverse to the central longitudinal (i.e. extending along the direction of travel) axis of the sweeping machine. The brush is driven to throw dirt picked up from the floor along a dirt-conducting channel and through a dirt delivery or discharge opening into the dirt container, usually in the form of a tub or large bucket. In the operating or sweeping position, the dirt container is located at the outer side of the dirt discharge opening with its opening edge tightly engaged (i.e. sealed) so that all of the dirt picked up from the floor is delivered into the container. The dirt container is arranged on at least one retracting arm (typically, on a pair of side arms) which, together with a parallel arm, forms a parallelogram lift assembly. In order to empty the dirt container, the lift arms are swiveled upwards by means of an hydraulic cylinder unit (or an electric linear actuator) so that the dirt container is moved into a raised position for dumping. During this lift motion the dirt container is maintained in a generally upright alignment by the parallelogram rod assembly to avoid spilling. With the dirt container in the raised position, the operator can drive the floor-cleaning machine to a place where the dirt container is moved above a large garbage container, into which the contents of the dirt container may be emptied by dumping.
In order to empty the contents of the dirt container in these existing designs, the operator manually loosens a holding device that rigidly connects the dirt container with the parallelogram rod assembly to prevent unintended rotation of the dirt container. When the holding device is loosened, the dirt container rotates, usually under gravity, around its mounting pivots at the distal end of the retracting arm so that the contents of the container are emptied into a larger refuse container for disposing.
After emptying the dirt container, it is necessary in these earlier machines, to manually return the dirt container to its initial use position in relation to the parallelogram rod assembly and manually to re-engage a holding device which secures the dirt container. However, it is also known to arrange (on the side of the dirt container) a hydraulic cylinder unit or an electric linear drive which, upon actuation, returns the dirt container from its emptying position into the usual alignment in relation to the parallelogram rod assembly so that the holding device can then be re-engaged.
Thus, in the known technical solutions one has had to perform manually the operation of returning the dirt container from its raised emptying position to the lowered use position, for which purpose the operator had to climb down from the floor-cleaning machine and manually rotate the dirt container, requiring considerable force or by using a supplemental power drive for rotating the dirt container from the emptying position to the normal collection or use position.